WO1999047607A1

WO1999047607A1 - Resin composition

Info

Publication number: WO1999047607A1
Application number: PCT/JP1999/001323
Authority: WO
Inventors: Yasuki Miura; Fukuo Kanno; Masataka Yokota
Original assignee: Asahi Glass Company Ltd.
Priority date: 1998-03-19
Filing date: 1999-03-17
Publication date: 1999-09-23
Also published as: US6780944B1; DE69938340T2; DE69938340D1; EP1065247A1; JP4223089B2; EP1065247A4; EP1065247B1; JPH11269383A

Abstract

A resin composition which comprises: 50 to 99.5 parts by weight of poly(phenylene sulfide); 0.5 to 50 parts by weight of a fluororesin which, when melted in a 330 °C nitrogen atmosphere and then cooled at a rate of 10 °C/min, has a solidification temperature of 237 °C or higher; and a filler and other optional ingredients in an amount of 0 to 250 parts by weight per 100 parts by weight of the sum of the polymers.

Description

Specification

Resin composition

Technical field

The present invention relates to a resin composition containing polyphenylene sulfide (hereinafter, referred to as PPS) and a fluororesin. More specifically, the dimensional accuracy of a molded article having a three-dimensional shape obtained by an injection molding method is significantly improved. A resin composition.

Background art

PPS is known as a resin with excellent heat resistance, solvent resistance, electrical properties, mechanical strength, dimensional stability, flame retardancy, etc.It is used for electric and electronic equipment parts and automotive parts materials. , Chemical equipment parts materials, other functional parts materials and so on.

Most of these uses injection molded parts. However, the required characteristics are subdivided.For example, some parts that have conventionally been processed by metal, such as cutting, require particularly high dimensional accuracy.

Substitution by PPS was difficult.

The reason is that PPS has a low degree of polymerization and has the property of being compounded with fiber reinforcing agents such as glass fiber and carbon fiber and inorganic fillers, etc., and can be used as engineering plastics. This is because a phenomenon occurs in which the dimensions of the molded product differ depending on the orientation direction and it is difficult to obtain a predetermined dimensional accuracy.

In addition, when inorganic fillers that do not cause orientation direction problems, such as glass beads, zinc oxide, and calcium carbonate, are blended into PPS, the problem of filler orientation during injection molding is solved, but molding The variation between shots is large, and the required dimensional accuracy cannot be satisfied.

For example, in order to obtain high dimensional accuracy of a molded article having a three-dimensional shape, a proposal for molding a composition containing PPS and a specific silane-treated silica powder into an optical fiber connector ferrule (Japanese Patent Laid-Open No. 6-2999072) and, tetrafurfuryl O b ethylene (hereinafter, TF referred E) _/ / Perufuruoro (alkyl Bulle ether) (hereinafter referred to as PAVE) copolymer (hereinafter referred to as PFA) PPS a 0.5 to 5% by weight with respect to Proposal for lining the blended composition by rotational molding (Japanese Patent Laid-Open No. 5-112690) However, the composition ratio is different from the composition of the present invention.

A proposal to obtain molded products with improved dimensional stability in oil and abrasion resistance by insert molding cylinder piston with a composition consisting of a specific amount of PP s, fluororesin, spherical filler, and fiber filler. JP-A-3-74681), a proposal to obtain a molded article from a composition having a homopolymer or copolymer of PPS, polyvinylidene fluoride (hereinafter referred to as PVdF), and TFE (Japanese Patent Laid-Open No. 5-29520) ), In a composition containing PPS, a fluororesin having a melting point of 320 ° C or less, and aminoalkoxysilane, a proposal to improve the mutual dispersibility of the PPS and the fluororesin, and to improve the mechanical strength of the molded product. Kaihei 8-53592), but it does not describe whether molded products with high dimensional accuracy can be obtained.

Disclosure of the invention

An object of the present invention is to provide a resin composition containing PPS, a fluororesin, and a filler, from which a three-dimensional molded article having high dimensional accuracy can be obtained by injection molding.

As a result of diligent studies, the present inventors have found that the above object can be achieved by blending a specific amount of a fluororesin having a higher solidification temperature than PPS into PPS, and have accomplished the present invention.

That is, the present invention relates to the following (a) and (b): (a) 50 to 99.5% by weight, (b) 0.5 to 50 in the total amount of (a) and (b). Provided is a resin composition containing the resin composition in a percentage by weight.

Further, the present invention provides the above resin composition containing the following (c) in a total amount of more than 0 to 250 parts by weight based on 100 parts by weight of the total of (a) and (b).

(a) Polyphenylene sulfide.

(b) A fluororesin having a solidification temperature (T _mc ) of 237 ° C or higher when cooled at a cooling rate of 10 ° CZ after being melted in a nitrogen atmosphere at 330 ° C.

(c) at least one selected from the group consisting of organic reinforcements, inorganic reinforcements and fillers. BEST MODE FOR CARRYING OUT THE INVENTION

PPS (a) used in the present invention is substantially a repetition of the structure represented by Formula 1. It is a random copolymer or block copolymer containing at least 70 mol%, preferably at least 90 mol%, of these repeating units. If this repeating unit is less than 70 mol%, it is difficult to obtain a composition that achieves the object of the present invention.

£ <2>-S expression (1

The copolymer units other than the repeating unit having the structure represented by the formula 1 are present in the PPS (a) in a proportion of less than 30 mol%, preferably less than 10 mol%, and do not lower the crystallinity of the polymer. It may contain an arylene sulfide structure unit represented by the following structure within the range.

― \

S 0 o -s-

[Ring +

(R represents an alkyl group, a nitro group, a phenyl group, an alkoxy group, a carboxylic acid group, or a carboxylic acid metal base.)

PP S (a) can be obtained by various known polymerization methods. A preferred method is to react sodium sulfide with p-dichlorobenzene in an amide-based solvent such as N-methylpyrrolidone or dimethylacetamide or a sulfone-based solvent such as sulfolane. At this time, to adjust the degree of polymerization, sodium hydroxide, lithium acetate, etc. It is preferred to add a metal carboxylate.

PP S (a) can be used after washing after polymerization.However, for example, it may be used after treatment with an aqueous solution containing an acid such as hydrochloric acid or acetic acid or a mixed solution of water and an organic solvent, or with a salt solution such as ammonium chloride. Even processed ones can be used. The melt index of P PS (a) is measured at a cylinder temperature of 300 ° C, a load of 5 kg, an orifice diameter of 2.095 mm and a length of 8 mm, and is preferably 0.1 to 500, particularly preferably. Is 1 to 300. If the melt index is less than 0.1, the fluidity during injection molding is poor, and if it exceeds 500, the mechanical strength of the molded product is low, making it unsuitable for industrial parts.

The fluororesin (b) is a fluororesin having a solidification temperature (T _mc ) of 237 ° C or higher when cooled at a cooling rate of 10 ° CZ after being melted in a nitrogen atmosphere of 330 ° C.

Specifically, PFA, TF EZ hexafluoropropylene (hereinafter, referred to as HFP) copolymer (hereinafter, referred to as FEP) may be mentioned.

PFA is preferably commercially available, in which the number of carbon atoms in the alkyl group of PAVE of the polymerization component is 1 to 6 and the polymerization unit based on PAVE is 1 to 5 mol%. As the PAVE, perfluro (propyl vinyl ether), perfluor (ethyl vinyl ether), perfluoro (methyl vinyl ether) are preferable, and particularly perfluoro (propyl vinyl ether) is preferable. The PF A may contain polymerized units based on two or more of these.

The FEP preferably has a polymerization unit of 1 to 20 mol% based on HFP and is commercially available.

Further, as the fluororesin (b) other than PFA and FEP, a PAVEZHFP / TFE copolymer, a polymerization component Z (PAVE and / or HFP) ZTFE copolymer other than PAVE and HFP, and the like may be used. In these copolymers, the polymerized units based on PAVE are 0 to 5 mol%, the polymerized units based on HFP are 0 to 20 mol%, and the total of the polymerized units based on PAVE and HFP is 1 to 20 mol%. % Is preferred. Specifically, for example, a copolymer containing 0.5 mol% of a polymerization unit based on perfluoro (propylbutyl ether) and 7.0 mol% of a polymerization unit based on HFP is used. Although the melt index of these fluororesins (b) is not particularly limited, it is measured under the conditions of 330 ° C, 5 kg load, orifice diameter 2.095 mm and length 8 mm. It is preferable for dispersion. Melt index measurement conditions are specified in ASTM D1238.

These fluororesins (b) can be produced by conventionally known various polymerization methods such as suspension polymerization, emulsion polymerization and solution polymerization.

The mixing ratio (a) / (b) of PPS (a) and fluororesin (b) in the composition of the present invention is 5050 to 99.5 / 0.5 by weight. Particularly, T O / S O S SZ 5 (weight ratio) is preferable. If the weight ratio of PPS is less than 50Z50, the fluororesin cannot clearly form islands, and if it exceeds 99.5 / 0.5, the amount of fluororesin will be small, and the effects of the present invention cannot be expected. In the matrix of the composition, the sea portion is preferably PPS, and the island portion is preferably formed of a fluororesin.

The effect that the molded article obtained from the composition of the present invention has high dimensional accuracy is likely to occur when the fluororesin solidifies before PPS (a) solidifies. Regarding the mechanism by which this effect occurs, (1) The pressure loss of the injection pressure is reduced when the molten composition passes through the gate of the mold by blending the fluororesin (b) with the PPS (a). This is probably because the fluororesin acts as an internal lubricant. As a result, the injection pressure is effectively transmitted to the composition in the mold. Fig. 1 shows a schematic cross-sectional view of the mold. 1 is a sprue, 2 is a runner, 3 is a pin gate, and 4 is a molded product.

(2) Fluororesin (b) solidifies before the gate seal, that is, with the holding pressure effectively acting on the composition in the mold, and PPS (a) solidifies after the gate seal. Through these two-stage solidification processes, the volume shrinkage after gate sealing is reduced. It is presumed that the effects of the present invention have been produced by the above-described effects, whereby the mold transferability and the variation between molding shots were suppressed.

Specifically, as shown in the examples, the molded product obtained by injection molding the composition of the present invention at a cylinder temperature of 330 ° C. and a mold temperature of 150 ° C. is a molded product A shown in FIG. It has excellent dimensional accuracy, with the dimensional difference of the B part and the difference between the maximum and minimum dimensions of the B part when formed by 100 shots are about 10 times smaller than before. Figure 2 is a cross-sectional view of the molded product. Indicates the dimensions and shape. The unit of the dimensions in Fig. 2 is mm, D 1 is 25.0 in diameter, D 2 is 19.0 in diameter, D 3 is 35.0 in diameter, D 4 is 24.6 in diameter, and D 5 is 22. 8, D6 is diameter 19.6, L1 is 35.0, L2 is 20.0, L3 is 5.4, L4 is 3.0, L5 is 8.0, L6 is 2.0 is there.

The composition of the present invention contains (c) an organic reinforcing material, an inorganic reinforcing material, or a filler in addition to (a) and (b), but based on 100 parts by weight of the total of (a) and (b). (C) May contain up to 250 parts by weight of organic reinforcement, inorganic reinforcement or filler. (A) If the component exceeds 250 parts by weight, injection molding is difficult. Also, injection molding can be performed without the component (c).

(c) Specific examples of the components include organic fillers of thermosetting resin powder, fly, mica, silica, talc, alumina, kaolin, calcium sulfate, calcium carbonate, graphite, titanium oxide, zinc oxide, riichi Examples include inorganic fillers such as bon black, glass fiber, bonbon fiber, inorganic reinforcing material with a weak force such as potassium titanate and aluminum borate, and organic reinforcing materials such as polyimide fiber. These components (c) may be used as they are, but it is preferable to use those that have been surface-treated with a silane coupling agent or the like before blending.

In addition, lubricants, stabilizers, pigments and the like may be added as necessary.

Adjustment of the resin composition of the present invention can be performed by charging the extruder into the hopper using a number of metering feeders, or by premixing using a tumbler, V mixer, hensile mixer, etc. A method of selecting a screw with a bidding function with a kneading machine, melting and kneading to make a pellet is used.

Hereinafter, the present invention will be described more specifically with reference to Examples (Examples 1, 2, 8, and 9) and Comparative Examples (Examples 3 to 7 and 10-13), but the present invention is not limited thereto. .

[Measurement of solidification temperature]

Using a thermal analysis system SSC 5200 (manufactured by Seiko Instruments Inc.), the sample was heated from normal temperature to 330 ° C at a rate of 10 ° C / minute under a nitrogen atmosphere, and maintained at 330 ° C for 5 minutes. The temperature was lowered from 10 ° C. to 100 ° C. in 10 ° C.Z for measurement.

[Raw materials used] PPS: Toray Co., Ltd., M-2100 (solidification temperature 237 ° C).

PTFE; Asahi Glass Co., Ltd., full-on PTFE L-150 J (no coagulation temperature). PF A: manufactured by Asahi Glass Co., Ltd., Aflon PF A P-61 (with a solidification temperature of 271). FEP: Aflon FEP (solidification temperature 241) manufactured by Asahi Glass Co., Ltd.

ETFE; Asahi Glass Co., Ltd., Aflon COPC88AX (coagulation temperature 230 ° C). Low melting point ETF E (hereinafter referred to as LM-ETFE); Aflon LM 740 (solidification temperature 206 ° C), manufactured by Asahi Glass Co., Ltd.

PVdF: NEOFLON VP 800 (coagulation temperature: 150 ° C), manufactured by Daikin. Glass fiber: 03MAFT 562, manufactured by Asahi Fiber One Glass Co., Ltd.

Spherical force: FB-35, manufactured by Denki Kagaku Kogyo.

Calcium carbonate: NS 200 manufactured by Nitto Powder Chemical Industry Co., Ltd.

No surface treatment was performed with a silane coupling agent before blending glass fiber, spherical silica, or calcium carbonate.

[Examples 1-6]

Table 1 shows the PPS and filler in the hopper of the first feeder and the fluororesin in the hopper of the second feeder of the same-direction twin-screw extruder with a kneading section having two kneading points. At a cylinder temperature of 320 ° C, a screw rotation speed of lOO rpm, the raw materials are kneaded while sucking with a vacuum pump from the vent, and the discharged strand is gradually cooled and then 3 mm long with a beretizer. The cylinder temperature of a molding machine of 30 tons for electric type mold clamping, which was cut into pieces to prepare a composition, was set to 330. The mold injected with the three pin-point gauging shown in Fig. 1 and engraved with a cylindrical sleeve with a flange was heated to 150 ° C with a heating medium, and the created composition was injected at an injection speed of 80 mm / sec. to obtain a molded article by injection molding under the conditions of SOO k gZcm ^2.

The outer diameter of points A and B in Fig. 2 was measured using a laser scan micrometer (manufactured by Mitutoyo Corporation) for the obtained molded article. The dimensional difference between parts A and B (wm) (hereinafter referred to as AZB dimensional difference) and the difference between the maximum and minimum dimensions of part B of a 100 shot molded product (wm) (hereinafter referred to as B dimensional difference) are shown. Shown in 1. [table 1 ]

[Examples 7 to 12]

At the weight ratio shown in Table 2, PPS and filler were put into the hopper of the first feeder of the kneading machine used in Examples 1 to 6, fluororesin was put into the hopper of the second feeder, and the glass fiber was put into the side feeder. The mixture was charged into an extruder in a one-way system and kneaded in the same manner as in Examples 1 to 6 to form a composition, and then molded to obtain a molded product. Table 2 shows the results of the measured outer diameter of the molded product. [Table 2] Composition Example 8 Example 9 Example 10 Example 11 Example 12 Example 13

P P S 90 90 90 90 90 90 Fluororesin P T F E 10

P F A 10

F E P 10

E T F E 10 LM- ET F E 10 P V d F 10 Filler Calcium carbonate 40 40 40 40 40 40 Glass fiber 60 60 60 60 60 60

AZB dimension difference 10 82 43 50 70 B dimension difference 8 68 25 19 33

Industrial applicability

INDUSTRIAL APPLICABILITY The resin composition of the present invention has extremely high dimensional accuracy of a molded article having a three-dimensional shape obtained by injection molding the resin composition, and is useful for structural materials and various parts in the fields of automobiles, home appliances, and electronics.

Claims

The scope of the claims

1. The following (a) and (b) are combined with (a) 50 to 9.5% by weight and (b) 0.5 to 50% by weight in the combined amount of (a) and (b). Resin composition containing in proportion.

(a) Polyphenylene sulfide.

(b) A fluororesin having a solidification temperature (T _mc ) of 237 C or more when cooled at a cooling rate of 10 CZ after being melted in a nitrogen atmosphere at 330 ° C.

2. The resin according to claim 1, further comprising the following (c) in a total amount of more than 0 to 250 parts by weight based on 100 parts by weight of the total of (a) and (b). Composition.

(c) at least one selected from the group consisting of organic reinforcements, inorganic reinforcements and fillers.

3. Claim 1 wherein (a) and (b) are contained in the combined amount of (a) and (b) at a ratio of (a) 7 to 95% by weight and (b) 5 to 3% by weight. Or the resin composition according to 2.

4. The resin according to claim 1, 2 or 3, wherein the fluorine resin has a melt index of at least 0.1 measured at 330 ° C, 5 kg load, orifice diameter 2.095 mm, length 8 mm. Composition.

5. The method according to any one of claims 1 to 4, wherein the fluororesin is a tetrafluoroethylene Z perfluoro (alkyl vinyl ether) copolymer or a tetrafluoroethylene / hexafluoropropylene copolymer. Resin composition.

6. the following (a) and the following (b ^1), while the total amount of (a) and ^{_{(b 1) (a) 70}} ~95 wt%, (b ¹⁾ in a proportion of 5 to 30 wt% A resin composition containing the following (c) in a total amount of 10 to 250 parts by weight based on 100 parts by weight of the total of (a) and (b ¹ ).

(a) Polyphenylene sulfide.

(b ¹ ) Tetrafluoroethylene noperfluoro (alkylbutyl ether) copolymer or tetrafluoroethylene hexafluoropropylene copolymer.

7. The melt index of the polyphenylene sulfide is 0.5 to 500 when measured under the measurement conditions of 330 ° C, 5 kg load, orifice diameter 2.095 mm and length 8 mm. The resin composition according to any one of the above.

8. A molded product obtained by injection molding the resin composition according to any one of claims 1 to 7.